This invention relates to an intake apparatus and an intake manifold for an internal combustion engine provided with a throttle valve, and more specifically to decreasing an abnormal noise when the throttle valve is rapidly opened.
In an internal combustion engine provided with a throttle valve, when the throttle valve is suddenly opened, a noise of an air flow is generated. Particularly in a case in which an intake manifold is made from a synthetic resin, the noise is further increased.
A patent document 1 (Japanese Patent Provisional Publication No. H11(1999)-013500), a patent document 2 (Japanese Patent Provisional Publication No. H11(1999)-141416), and a patent document 3 (Japanese Patent Provisional Publication No. 2002-155817) disclose an intake apparatus provided with a grid-shaped rectifier member (wire netting member) for rectifying the flow immediately downstream of the throttle valve, and an intake apparatus provided with a raised portion (projection) immediately downstream of the throttle valve to generate turbulence positively, for reducing the noise caused by the joining of the flows passing through the throttle valve.